Tensioning apparatus

ABSTRACT

For feeding wire or other elongate flexible stock along a predetermined path, apparatus comprising a constant feeder at one location along the path, an intermittent feeder farther along the path, a portion of the stock between said feeders being free to move in a direction transverse of the path, and a regulator in said portion for maintaining uniform tension in the stock, said regulator comprising a guide bearing on said portion and means yieldingly pressing the guide in said direction, said means including a chamber containing gas under pressure and an actuator responsive to said pressure for actuating said guide, whereby the guide can react quickly in response to rapid jerks of said feeder.

United States Patent 1 [72] Inventor William E. Whitney Belmont, Mass. [21] Appl. No. 772,172 [22] Filed Oct. 31, 1968 [45'] Patented Jan. 19, 1971 [73] Assignee Comstock & Wescott, Inc.

Cambridge, Mass.

a corporation of Massachusetts [54] TENSIONING APPARATUS 5 Claims, 1 Drawing Fig.

[52] [1.8. CI 1 226/117, 226/ 195 [51] Int. Cl B65h 17/42 [50] Field of Search 226/44, I 117, 195

[56] References Cited UNITED STATES PATENTS 1,626,409 4/ 1927 Gwinn 2,544,467 3/1951 Michel 226/44X 3,049,308 8/1962 Lang 226/44X 3,322,315 5/1967 Eberlin 226/195X Primary Examiner-Richard A. Schacher Attorney-Roberts, Cushman & Grover ABSTRACT: For feeding wire or other elongate flexible stock along a predetermined path, apparatus comprising a constant feeder at one location along the path, an intermittent feeder farther along the path, a portion of the stock between said feeders being free to move in a direction transverse of the path, and a regulator in said portion for maintaining uniform tension in the stock, said regulator comprising a guide bearing on said portion and means yieldingly pressing the guide in said direction, said means including a chamber containing gas under pressure and an actuator responsive to said pressure for actuating said guide, whereby the guide can react quickly in response to rapid jerks of said feeder.

, TENSIONING APPARATUS This invention relates to apparatus for handling elongate,

' flexible stock such as wir'e, film, ribbon, etc., andmore particularly to apparatus for'maintaining uniform tension in the stock as it is fed into amachine intermittently. Heretofore it has been proposed to accomplish this result by providing adepending loop in the stock between the supply reel and the feeder and floating a weighted roller inthe bottom of the loop. It has also been proposed to press a guide roller against a stretch of the stock with a spring. While these devicesare satisfactory for relatively slow apparatus such as cinemato graphic camerasand projectors they are inadequate for ap- Y the entering stock be slacked off between intermittent advances, and to avoid damage to the stock as a, result of the quickjerks. v

According to this invention the apparatus comprises a feeder for intermittently I, feeding stock from a supply reel along a predetermined path in which a portion of the stock is free to move in a direction transverse of the path, and a regulator intermediate the reel and feeder for maintaining uniform tension in the stock, the regulatorcomprising a guide'bearing on said portion and means yieldingly pressing the guide in said direction, the aforesaid means including a chamber containing gas under pressure and an actuator responsive to said pressure for actuating the guide, whereby the guide can react quickly in response to rapid jerks of the feeder. Preferably the apparatus also comprises a gas reservoir I communicating with the aforesaid chamber, the capacity of the reservoir being larger than that of the chamber, and means for maintaining the pressure in the reservoir approximately constant. in the preferred embodiment the aforesaid chamber is a cylinder and the actuator comprises a piston in the cylinder.

In a more specific aspect the apparatus comprises a constant feeder at one location along the aforesaid path, an intermittent feeder farther along the path, a p rtion ofthe stock between said feeders being free to move in a direction transverse of the path, and a regulator in said portion for maintaining uniform tension in the stock, said regulator comprising a guide bearing on said portion and means yieldingly pressing the guide in said direction. said means including a chamber containing gas under pressure and an actuator responsive to said pressure for actuating said guide, whereby the guide can I react quickly in response to rapid jerks of said feeder.

herewith.

As disclosed in the aforesaid applicationthe machine comprises an arm I which swings back and forth about a pivot 2 between the two positions shown in full and broken lines to wind wire W over a series of pins 3, which are progressively advanced into the path of the wire, the arm being oscillated by a rotor 4 through an eccentric 6 or other suitable means for converting rotary motion into oscillating motion. As the arm oscillates in each direction the wire is jerked forward, as it reverses its direction the wireslacks off and as hereinafter explained the slack is taken up by the present invention so that the wire is kept taut all the time.

In the preferred embodiment the wire is fed from a reel 7 at a constant rate by a pulley 8 about-which the wire makes at least one turn so as not to'slip on the wire. the pulley being driven by a motor 9 through reduction gearing ll. From the pulley 8 the Wire IS pulled y oscillator over a series of pulleys l2, l3. l4, l5 and 16 and thence betweentwo rollers 17 and 18, the pulleys f3 and floating in two loops [9 and 20 of the wire. As the oscillator moves from the position shown in thefigure to midposition it has a backward component of movement and as it swings from midposition to side position it 3 at 2 6. The cylinder is connected to a chamber 27 which contains air or other gas and in which the pressure is maintained constant by a pressure regulating valve 28 connected to a suitable source of pressure.

From the foregoingit will be understood that with the oscillator l feeding the wireat an average velocity equal to the constant velocity of thefeeder 8, as the oscillator slacks off the wire, the slack is taken up by the pressure in cylinder 25.

By making the capacity of the reservoir much larger than that of the cylinder,- the pressure in the cylinder is kept approximately constant as the piston moves back and forth and, by making the parts l3, 15, 21, 23 and 24 small and of-light material, the tension on the wire may be kept uniform even when the oscillator jerks the wire at afrequency as high as oscillations per second or higher.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Apparatus for handling wire comprising a supply reel, a first feeder for continuously feeding wire from a reel, a second feeder for intermittently feeding wire from the first feeder along a predetermined path in which a portion of the wire is movable in a direction transverse of the path, the feeder having alternate components of movement in opposite directions lengthwise of said path,and a regulator intermediate the two feeders for maintaining uniform tension in the stock, said por tion comprising a plurality of depending loops and said regulator comprising a roller floating in each of said loops, and means yieldingly pressing the rollers downwardly, said means including a chamber containing gas under pressure and an ac- -tuator responsive to said pressure for actuating said rollers,

whereby the regulator can react quickly in response to rapid jerks of said feeder.

2. Apparatus according to claim 1 wherein said chamber is a cylinder and said actuator comprises a,piston in the cylinder.

3. Apparatus according to claim 1 further characterized by a gas reservoir communicating with said chamber, the capacity of the reservoir being larger than that of the chamber.

4. Apparatus according to claim 3 further characterized by means for maintaining the pressure in the reservoir approximately constant. e

' 5. ,Apparatus according to claim 1 further characterized by a common shaft for said rollers. 

1. Apparatus for handling wire comprising a supply reel, a first feeder for continuously feeding wire from a reel, a second feeder for intermittently feeding wire from the first feeder along a predetermined path in which a portion of the wire is movable in a direction transverse of the path, the feeder having alternate components of movement in opposite directions lengthwise of said path, and a regulator intermediate the two feeders for maintaining uniform tension in the stock, said portion comprising a plurality of depending loops and said regulator comprising a roller floating in each of said loops, and means yieldingly pressing the rollers downwardly, said means including a chamber contaIning gas under pressure and an actuator responsive to said pressure for actuating said rollers, whereby the regulator can react quickly in response to rapid jerks of said feeder.
 2. Apparatus according to claim 1 wherein said chamber is a cylinder and said actuator comprises a piston in the cylinder.
 3. Apparatus according to claim 1 further characterized by a gas reservoir communicating with said chamber, the capacity of the reservoir being larger than that of the chamber.
 4. Apparatus according to claim 3 further characterized by means for maintaining the pressure in the reservoir approximately constant.
 5. Apparatus according to claim 1 further characterized by a common shaft for said rollers. 